/**
 * Copyright (c) 2005-2010 springside.org.cn
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * 
 * $Id: EncodeUtils.java 1211 2010-09-10 16:20:45Z calvinxiu $
 */
package com.alter.utils.encode;

import java.io.UnsupportedEncodingException;
import java.net.URLDecoder;
import java.net.URLEncoder;

import org.apache.commons.codec.DecoderException;
import org.apache.commons.codec.binary.Base64;
import org.apache.commons.codec.binary.Hex;
import org.apache.commons.lang.StringEscapeUtils;
import org.springframework.util.Assert;

/**
 * 各种格式的编码加码工具类.
 * 
 * 集成Commons-Codec,Commons-Lang及JDK提供的编解码方法.
 * 
 * @author calvin
 */
public class EncodeUtils {

    private static final String DEFAULT_URL_ENCODING = "UTF-8";

    /**
     * Hex编码.
     */
    public static String hexEncode(byte[] input) {
	return Hex.encodeHexString(input);
    }

    /**
     * Hex解码.
     */
    public static byte[] hexDecode(String input) {
	try {
	    return Hex.decodeHex(input.toCharArray());
	} catch (DecoderException e) {
	    throw new IllegalStateException("Hex Decoder exception", e);
	}
    }

    /**
     * Base64编码.
     */
    public static String base64Encode(byte[] input) {
	return new String(Base64.encodeBase64(input));
    }

    /**
     * Base64编码, URL安全(将Base64中的URL非法字符如+,/=转为其他字符, 见RFC3548).
     */
    public static String base64UrlSafeEncode(byte[] input) {
	return Base64.encodeBase64URLSafeString(input);
    }

    /**
     * Base64解码.
     */
    public static byte[] base64Decode(String input) {
	return Base64.decodeBase64(input);
    }

    /**
     * URL 编码, Encode默认为UTF-8.
     */
    public static String urlEncode(String input) {
	try {
	    return URLEncoder.encode(input, DEFAULT_URL_ENCODING);
	} catch (UnsupportedEncodingException e) {
	    throw new IllegalArgumentException("Unsupported Encoding Exception", e);
	}
    }

    /**
     * URL 解码, Encode默认为UTF-8.
     */
    public static String urlDecode(String input) {
	try {
	    return URLDecoder.decode(input, DEFAULT_URL_ENCODING);
	} catch (UnsupportedEncodingException e) {
	    throw new IllegalArgumentException("Unsupported Encoding Exception", e);
	}
    }

    /**
     * Html 转码.
     */
    public static String htmlEscape(String html) {
	return StringEscapeUtils.escapeHtml(html);
    }

    /**
     * Html 解码.
     */
    public static String htmlUnescape(String htmlEscaped) {
	return StringEscapeUtils.unescapeHtml(htmlEscaped);
    }

    /**
     * Xml 转码.
     */
    public static String xmlEscape(String xml) {
	return StringEscapeUtils.escapeXml(xml);
    }

    /**
     * Xml 解码.
     */
    public static String xmlUnescape(String xmlEscaped) {
	return StringEscapeUtils.unescapeXml(xmlEscaped);
    }

}
